This program is an application-level gateway, or proxy, designed to allow
mail retrieval from POP3 servers by systems that either:

        (a) are behind a firewall or screening router OR
        (b) do not have an assigned IP number OR
        (c) must share a SLIP/PPP connection on another system

It connects to the POP3 server on behalf of the client, performs the login
and then passes data both ways until either the client or the server shut
down the connection. In the meanwhile, the connection will appear to have
originated on the host running the proxy.
